Biology subjects

Afghah, F.

Publications and source records attributed to Afghah, F..

4 recordsLinked to original sources

bioRxiv2026

2D Skeletal Muscle Thin Film Actuators Enhance Efficiency of Biohybrid Robots

Biohybrid robots combining compliant synthetic support structures with biological actuators could enable future applications ranging from precision microsurgery to unmanned exploration. Machines actuated by living skeletal muscles are capable of adaptive behaviors, such as sensing and responding to environmental stimuli in real-time, offering functional advantages over non-biological actuators. However, typical skeletal muscle-powered biohybrid robots depend on 3D tissues which require large cell volumes and offer limited control of muscle fiber alignment, thus reducing efficiency of force generation and transduction. Here, we present a locomotive biohybrid robot powered by 2D monolayers, or thin films, of precisely aligned skeletal muscle fibers on a micropatterned hydrogel skeleton. We demonstrate how varying skeleton design parameters, ranging from material stiffness to microscale topology, impacts muscle fiber alignment and resultant actuation strains, generating forces 10X higher than previous 2D skeletal muscle actuators, improving untethered actuation longevity by [~]4500X from < 10 minutes to > 30 days, and increasing efficiency of muscle force output (force per unit volume of muscle) by 20X as compared to 3D muscles. Utilizing our optimized design for skeletal muscle thin films, we create a multi-limbed robot composed of independent muscle-powered fins capable of on/off control and frequency-dependent speed control. With these control inputs, we achieve steered multi-directional locomotion at speeds up to 4 body lengths per minute in straight movement and 1200 degrees per minute in rotational movement, highlighting potential for such actuators to be transformed into long-lasting functional soft robots.

bioengineering↗

bioRxiv2025

Limb-on-a-Chip: An All-Hydrogel Platform for Scalable and Reproducible Engineering of Neuromuscular Tissues

Diseases or injuries that impact neuromuscular tissues have a severe negative impact on human health, mobility, and quality-of-life, motivating the development of tissue engineered in vitro models of the motor control system. Current neuromuscular organoids and organ-on-a-chip platforms either rely on stochastic self-assembly that limits reproducibility or require complex microfabrication processes that preclude high-resolution imaging and scalable functional analysis. We have developed a Limb-on-a-Chip platform that addresses key challenges of current model systems by enabling reproducible and scalable manufacturing of neuromuscular tissues compartmentalized into "spinal cord" and "limb" chambers, while promoting biochemical crosstalk between cell types. Our fabrication method leverages 3D printed molds to perform 1-step micropatterning of an all-hydrogel chip containing precise features to guide muscle fiber alignment and motor neuron axonal outgrowth. We demonstrate the ability to co-culture motor neurons and skeletal muscles within this hydrogel platform, enabling tissue-wide readouts of muscle force as well as single cell-resolution measurements of muscle fiber calcium activity. Our accessible method for fabricating reproducible in vitro neuromuscular models that are compatible with high-resolution imaging and functional readouts provides a powerful new tool for investigating the neuromuscular interface in health and disease.

bioengineering↗

bioRxiv2025

Enabling Real-Time Process Analysis in Embedded Bioprinting with a Modular In Situ Monitoring Platform

Real-time monitoring and in situ data analysis are increasingly vital for enhancing precision, reproducibility, and defect detection in embedded bioprinting. As interest grows in improving the capabilities of existing bioprinting systems, accessible strategies for integrating real-time sensing and analysis are becoming essential to ensure consistent quality and to optimize printing parameters. Here, we present a modular, low-cost, and printer-agnostic platform that combines a compact sensing architecture with an effective image analysis pipeline to enable in situ process monitoring, defect detection, and print quality assessment. the platform integrates a digital microscope aligned on-axis with the extrusion printhead to capture high-resolution images during fabrication. We applied and compared two segmentation methods, thresholding and the Segment Anything Model (SAM) on in situ and ex situ datasets acquired via confocal fluorescence imaging, finding SAM to yield stronger correlations (R = 0.85-0.86) between in situ and ex situ measurements. Additionally, we demonstrated that 2D in situ images provide reliable approximations of 3D filament geometries, supporting their use for real-time morphological assessment. the system also revealed pressure-related effects on the diameters, and a critical velocity threshold for printing stability, highlighting its value for process optimization. together, these findings establish the approach as a low-cost, scalable and adaptable solution that can be readily implemented across embedded bioprinting workflows, offering a practical path toward greater reproducibility and automation.

bioengineering↗

bioRxiv2024

2.5D Actuating Substrates Enable Decoupling the Mechanical and Biochemical Effects of Muscle Exercise on Motor Neurons

Emerging in vivo evidence suggests that exercise impacts peripheral nerves, but the difficulty of isolating and studying the muscle-specific impact on motor neurons in vivo, as well as the inability to decouple the biochemical and mechanical impacts of exercise in this setting, motivate investigating this phenomenon in vitro. In this study, we show that tuning the mechanical properties of fibrin hydrogels can generate stable 2.5D motor neuron and contractile skeletal muscle cultures that enable long-term efficient secretome harvesting from exercised tissues. Motor neurons stimulated with muscle-secreted cytokines significantly upregulate neurite outgrowth and migration, with an effect size dependent on exercise intensity. Actuating magnetic microparticles embedded within 2.5D substrates enabled us to dynamically stretch motor neurons and non-invasively mimic the mechanical effects of exercise, revealing that dynamic stretch has an equally significant impact on axonogenesis. RNA sequencing revealed different transcriptomic signatures between groups, with biochemical stimulation having a significantly greater impact on cell signaling related to axon growth and development, neuron projection guidance, and neuron-muscle synapse maturation. Our study thus leverages 2.5D actuating substrates to robustly validate a hypothesized role for muscle exercise in regulating motor neuron growth and maturation through both mechanical and biochemical signaling.

bioengineering↗